Extreme rainfall in Hong Kong, Brazil and Greece leaves dozens dead after flash flooding

Unprecedented flooding on multiple continents around the world has left dozens dead and displaced thousands since the start of September.

The extraordinary scenes of devastation from extreme rainfall have become commonplace this summer, with record-setting downpours hammering places like Vermont, India, China, Spain, South America and Japan with alarming frequency.

Here’s a rundown of the most recent rainfall disasters:

Hong Kong sets record for most rain in a single hour

One month after extreme rains associated with Typhoon Doksuri killed more than 80 people in northern China, a historic deluge hit the southern part of the country, including Hong Kong. It dumped a record-setting 6.2 inches of rain in an hour, killing at least two people and injuring over 140, Fox Weather reported.

The rainstorms transformed city streets into raging rivers, damaging cars and storefronts and shuttering the stock market on Friday, Bloomberg reported.

“This would have been virtually impossible had it not been for climate change,” Lam Chiu-ying, a former director of the Hong Kong Observatory, told the South China Morning Post on Friday. “We have to be prepared for what used to be extreme but what could become normal.”

Brazil pummeled

At least 39 people were killed this week when an extratropical cyclone unloaded several inches of rain across the southern state of Rio Grande do Sul. More than 6,000 people have been displaced in the torrential downpours.

“The city went into upheaval. People began to climb onto the roofs of houses. On Tuesday, we ran out of internet and telephone service, and it was even more desperate. Even today, it is difficult to walk the streets; there is a lot of destruction,” Júlio Saldanha, a resident of the southern city of Estrela, told Brazil Reports.

Firefighters and military police are taking part in rescue efforts, with helicopters being used to pluck people off the roofs of flooded homes, Euronews reported.

"There are still people missing. The death toll might climb higher," Mayor Mateus Trojan of Muçum told Radio Gaucha. "The town of Muçum as we knew it no longer exists."

Greece, Turkey and Bulgaria feel Daniel’s wrath

At least 16 people were killed this week after extreme rainfall produced by Storm Daniel pummeled Greece, Turkey and Bulgaria, with raging floodwaters leveling buildings and bridges in many locations.

As of Thursday, rescuers had saved approximately 800 people trapped by the flooding, CNN reported.

With the storm stalled over Greece, the city of Zagora set a new record, receiving 21 inches of rain in 10 hours.

Earlier this summer, Greece had experienced drought conditions that helped spark raging wildfires. Now the country faces a different calamity, but one that Prime Minister Kyriakos Mitsotakis also attributes to rising global temperatures.

“I am afraid that the careless summers, as we knew them ... will cease to exist, and from now on the coming summers are likely to be ever more difficult,” he said, according to the International Travel & Health Insurance Journal.

How climate change is increasing extreme rainfall events

As global temperatures continue to rise in tandem with the burning of fossil fuels, the amount of moisture held by the Earth’s atmosphere also rises. Studies have shown that for every degree Celsius of warming, the atmosphere holds 7% more moisture.

“When it rains, it’s increasingly likely to pour, just because of basic thermodynamics, and when it’s not raining, when it’s sunny and hot — and, of course, increasingly hot due to climate change — it’s going to be easier to evaporate that water back into the atmosphere, leading to more arid conditions during that period, more rapidly intensifying droughts,” UCLA climate scientist Daniel Swain told Yahoo News earlier this year.